The invention relates to a device and method for controlling and monitoring liquid draining from the uterus during medical procedures within the uterus, and more particularly to a device and method permitting the introduction of liquid into the uterus and controlling and monitoring drainage from the uterus while simultaneously permitting the entry into and manipulation within the uterus of a medical instrument or device.
In their practice, gynecologists often find it useful to introduce liquid into the uterus as an aspect of treatment or of a diagnostic procedure. Currently, a gynecological procedure may be performed in a surgical suite at a hospital where the patient may be draped to catch any such liquid if it drains from the uterus and direct the flow of the liquid to a container. The surgical suite is also generally designed and staffed to deal with spillage and facilitate clean-up. The procedure may be performed in an office setting, however, which generally lacks the staff and facilities of the surgical suite for dealing with any such spillage.
As liquid in the uterus drains out through the cervix into the vagina and then out of the body, several problems may be created. One problem that may result is the mess and hazard of spillage. The liquid may spill out into the area where a gynecologist is working, creating an inconvenient situation. Such spillage is particularly a problem where the procedure involves the use of small diameter instruments inserted through the cervix, the use of low viscosity liquid in the uterus, the dilation of the cervix, and where the procedure is performed in an office setting rather than in a surgical suite.
Contact between various tissue and the liquid draining from the uterus may also be a problem. The liquid used may have certain properties such as high temperature so that the physician would prefer not to expose vaginal tissue, or the skin of the patient or physician to contact with the liquid. Therefore it would be advantageous to devise an apparatus and method to control the drainage of such liquid to prevent exposing the patient's vaginal tissue or the skin of the patient or doctor to such liquid.
A third potential problem created by uncontrolled drainage is the inability to monitor the amount of fluid absorbed by the patient during the procedure. The interior of the uterus is highly vascularized, and the uterus is open to the peritoneal cavity through the fallopian tubes. As a result, liquid introduced into the uterus is sometimes absorbed by the patient's bloodstream or may migrate through the fallopian tubes into the peritoneal cavity. It is important to monitor the amount of liquid input and the amount drained to estimate the amount of such liquid absorbed into the patient's system so that a physician can take appropriate action if the amount absorbed by the patient indicates that action is necessary. Such action by a physician might include, for example, stopping the procedure, administering drugs such as diuretics, or both.
If the liquid drains out of the patient onto the floor or soaks into surgical drapes, it becomes difficult to determine how much of the liquid input during a procedure drained out and how much was absorbed by the patient. A method of accurately monitoring the outflow of liquid from the uterus would be advantageous both when the procedure is performed in an office setting and when the procedure is performed in a surgical suite.
One important and common procedure used by gynecologists to visualize the interior of the uterus is hysteroscopy. A hysteroscope is a specialized endoscope which, in hysteroscopy, is introduced into the patient through the vagina and the cervix to view the interior surface of the uterus. The hysteroscope may be either a contact hysteroscope that provides viewing of the tissue against which the tip of the hysteroscope is placed, or may be a panoramic hysteroscope which may view the tissue at some distance from the tip of the hysteroscope and, as the name implies, provide a more panoramic view.
The inside of the uterus generally has its walls closely opposed so that distension of the uterus is necessary to create sufficient separation between the walls for viewing by a hysteroscope, particularly the panoramic hysteroscope. Therefore hysteroscopy usually begins with distending the interior cavity of the uterus by introduction of distension media into the uterus under pressure to separate the uterine walls and create space for viewing the endometrial tissue of those walls. Once the uterus is thus distended, it is generally maintained in the distended condition by maintaining the distension media within the uterus under slight pressure.
Hysteroscopes may be diagnostic or operative. Diagnostic hysteroscopes are used primarily to view and evaluate the condition of the tissue within the uterus. Operative hysteroscopes are generally carried within a stainless steel tube called a surgical sheath. The surgical sheath may contain various surgical tools such as semi-rigid sensors, clamps, or surgical electrodes that may be manipulated from outside the body to perform procedures such as biopsy of tissue, resectoscopic surgery, laser surgery and electrosurgery in a liquid environment.
The hysteroscope, whether diagnostic or operative, is generally tubular in shape and is inserted through the cervix into the uterus. The portion of a typical hysteroscope positioned within the uterus terminates in a lens and is provided with cold light generally from a light source located outside the body which is filtered and transmitted into the uterus by fiber optics. The portion of the hysteroscope which extends out of the patient's body may terminate in an eyepiece for viewing through the lens or may be fitted to a video camera so that the image from the lens may be displayed on a video screen and simultaneously recorded. Both types of hysteroscopes are generally contained within a stainless steel sheath that has channels, for example, for the inflow of a distension media and for the aspiration of fluid. If the hysteroscope is an operative hysteroscope, the surgical sheath will generally have additional channels for various surgical instruments. Because of the additional channels, operative hysteroscopes are generally but not always thicker in diameter than diagnostic hysteroscopes.
The typical diagnostic hysteroscope is usually tubular in shape and has an outer diameter of 3 to 5 millimeters. The typical operative hysteroscope may be 9 millimeters in diameter. Improvements in surgical instruments have provided surgical electrodes as small as 1.7 millimeters and allow operative hysteroscopes as small as 5 millimeters to be used for electrosurgical procedures. The smaller diameter is generally preferable because it is less traumatic to the patient. However, electrosurgical procedures are generally performed in a liquid environment, in which case the introduction of a significant amount of liquid may be involved. Any leakage problem could be exacerbated if a smaller diameter instrument is used.
The uterus is open through the cervix into the vagina, the vagina is open out of the patient, and distension fluid initially introduced into the uterus will drain out of the patient if not contained. Even if the distension media initially introduced into the uterus does not significantly drain out, it is often necessary to introduce additional distension media into the uterus during a hysteroscopic procedure. Particularly with a hysteroscope having a small diameter or with distension medium having low viscosity, the fit between the hysteroscope and the cervix may be loose enough to allow the distension medium to drain out during hysteroscopy. This problem is exacerbated if the cervix is dilated for any reason.
Various methods for forming a tighter fit between the cervix and an inserted hysteroscope have been suggested, including the use of specialized tenacula to compress the cervix around the inserted hysteroscope, or the use of a purse string suture to tighten the cervix around the inserted hysteroscope. These methods involve additional time and manipulation and may increase the trauma to the tissue manipulated in this way. A simple, fast and less traumatic method of controlling the drainage of distension media would be advantageous.
Hysteroscopy may be performed in a hospital setting such as a surgical suite, or if appropriate, in a doctor's office. It is often preferable to perform such procedures in the office setting because hysteroscopy performed in an office is generally more convenient, less expensive and less time consuming, and may be accomplished using fewer personnel than when it is performed in a hospital. However, uncontrolled drainage of distension media may make such procedures difficult to perform in the office setting. In both office and hospital settings, the inability to accurately monitor the amount of fluid absorbed by the patient, and undesirable contact between vaginal tissue or skin and liquid used in the procedure are problems.
Some hysteroscopes have a viewing direction in line with the surgical sheath generally referred to as 0 degrees, and some have a viewing line angled outward at 30 degrees from the line of the surgical sheath. Anatomical features of the uterus that gynecologists commonly need to view by hysteroscopy are the tubal ostia which are at the entrance of the fallopian tubes into the uterus. In cross-section, the uterus is generally shaped as an inverted triangle, with the cervix at the lower point open to the vagina through the external os, and the fundus of the uterus, the area between the two tubal ostia, being the top line of the inverted triangle. In order to view the tubal ostia, a hysteroscope with a 0 degree line of sight inserted through the cervix may have to be angled significantly toward each upper corner of the uterus. If the hysteroscope is inserted directly into the cervix, such manipulations may result in twisting and other movement of the hysteroscope directly against the tissues of the cervix, the cervical canal and, in extreme cases, the uterus. A device whereby an instrument inserted into the cervix and moved and manipulated, for example angled for a view toward the tubal ostia, without putting direct pressure against the internal tissue of the cervix would be advantageous.
The present invention provides a convenient device and method to address and ameliorate the above described problems.